According to the Docs on Materialize Forms:
In addition, you will need a separate call for any dynamically generated select elements your page generates
So the best way is to just re-bind the generated select with an additional call to .material_select().
For re-usability, you can set up a listener when the elements have changed and then trigger that listener whenever you update the original select
// 1) setup listener for custom event to re-initialize on change
$('select').on('contentChanged', function() {
$(this).material_select();
});
// 2a) Whenever you do this --> add new option
$selectDropdown.append($("<option></option>"));
// 2b) Manually do this --> trigger custom event
$selectDropdown.trigger('contentChanged');
This has the benefit of only needing to update the particular select element that has changed.
Demo in jsFiddle & Stack Snippets:
$(function() {
// initialize
$('.materialSelect').material_select();
// setup listener for custom event to re-initialize on change
$('.materialSelect').on('contentChanged', function() {
$(this).material_select();
});
// update function for demo purposes
$("#myButton").click(function() {
// add new value
var newValue = getNewDoggo();
var $newOpt = $("<option>").attr("value",newValue).text(newValue)
$("#myDropdown").append($newOpt);
// fire custom event anytime you've updated select
$("#myDropdown").trigger('contentChanged');
});
});
function getNewDoggo() {
var adjs = ['Floofy','Big','Cute','Cuddly','Lazy'];
var nouns = ['Doggo','Floofer','Pupper','Fluffer', 'Nugget'];
var newOptValue = adjs[Math.floor(Math.random() * adjs.length)] + " " +
nouns[Math.floor(Math.random() * nouns.length)];
return newOptValue;
}body { padding: 25px}<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/css/materialize.min.css" rel="stylesheet">
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/js/materialize.min.js"></script>
<button class="waves-effect waves-light btn" id="myButton">
Add New Option to Dropdown
</button>
<select id="myDropdown" class="materialSelect">
<option value="Happy Floof">Happy Floof</option>
<option value="Derpy Biscuit">Derpy Biscuit</option>
</select>